Related links:

Coupled Ocean-Atmosphere Models

Scientists use computer models to help them understand and predict the behaviors of Earth's atmosphere and oceans. These models, which run on supercomputers, are extremely complex. Some models only cover the atmosphere, while others only deal with the oceans. A third type of model combines ocean and atmospheric models into a single integrated framework in which interactions between the oceans and atmosphere are a key feature. These combined models are referred to as "coupled models".

Let's look at an example to clarify the distinction between coupled and uncoupled models. Atmospheric models that are used to assess climate change are very much concerned with the amount of carbon dioxide (CO2) in the air. Some processes, such as fossil fuel burning, add carbon dioxide to the atmosphere. Other processes remove carbon dioxide from the air. The world's oceans absorb large amounts of CO2, for instance. In an uncoupled model of the atmosphere, the portion of the model that portrays the oceans always stays the same, no matter how much CO2 the seas absorb. In a coupled model, on the other hand, the ocean model would change over time as the levels of carbon dioxide in the oceans increased. The oceans would gradually become saturated with CO2 and would thus be able to absorb less and less from the atmosphere. This change would, in turn, alter the behavior of the atmosphere part of the model.

It probably seems obvious to you that a coupled model is more realistic. Why don't scientists always use coupled models? Coupled models are much more complex, so it takes a lot more effort to make sure they are working correctly. The greater level of complexity also means that coupled models take much longer to run, even on supercomputers. Some scenarios can be modeled pretty well with uncoupled models. Other situations demand the more complex coupled models.

You might also be interested in:

Carbon dioxide is a colorless and non-flammable gas at normal temperature and pressure. Although much less abundant than nitrogen and oxygen in Earth's atmosphere, carbon dioxide is an important constituent...more

Air pollution comes from many different sources. Natural processes that affect air quality include volcanic activity, which produce sulfur, chlorine, and ash particulates, and wildfires, which produce...more

How do researchers know whether a computer model of Earth’s climate is accurate? To test accuracy of a model, its results are compared to observed measurements. This is often done by comparing climate...more

Some scientific problems and processes are so complex that you need SUPERCOMPUTING power to tackle them! Just what is a supercomputer? A supercomputer is a computer that is among the largest, fastest or...more

A gyre is another name for a swirling vortex. Ocean gyres are large swirling bodies of water that are often on the scale of a whole ocean basin or 1000’s of kilometers across (hundreds to thousands of...more

An aquifer is the name for a layer of rock which is capable of holding a large amount of water. Some layers are better at holding water than others, for example a layer of sandstone can hold a good deal...more

Carbonate is a name for rocks and minerals which contain a certain form of carbon/oxygen compound known as CO32-. (CO32- is also known as the molecule carbonate). Limestone is an example of a calcium carbonate,...more